It is widely known that internal tumors can succumb to radio surgery and that kidney stones can be broken up into gravel by impinging ultra sound energy on them. Tumors in the thoracic cavity, or elsewhere in the body can be attacked by impinging laser, X-rays, or other high-energy radiation beams on them with sufficient power to kill the tumor cells. (Hereinafter, the term X-ray will be used in a generic sense to encompass many different kinds of radiation beams, such as X-rays, gamma rays, laser beams, ultra sound, and other similar radiation scalpels/tools) Similarly, stones accumulated in the kidney, gall bladder and the like can be treated with other radiation beams, such as ultra sound, in order to break up the stones into gravel that is small enough to pass out of the patient's system. It is obvious that, if the direction of the high-energy radiation beam is not exactly where it is supposed to be, even if it is off very slightly, the consequences are that the procedure is either ineffective or not completely effective. That is, for example, either that the entire tumor is not destroyed, or rendered necrotic, (because the high energy X-ray beam doesn't reach to the edge of the tumor) or normal, healthy tissue is destroyed, or rendered necrotic, (because the X-ray beam impinges on tissue outside the periphery of the tumor). Therefore, technicians go to extreme lengths to insure that the X-ray beam is properly focussed exactly where the tumor, or other feature being treated, is.
It will be clear, however, that the patient being treated is breathing throughout the high-energy radiation treatment. Thus, the thoracic cavity (or other locations under treatment) is almost constantly moving as a function of normal breathing. Further, there is the risk that the patient will inadvertently sneeze or cough during treatment, which would severely impact on the accuracy of the impingement of the high-energy radiation. As the patient breathes, his chest moves and thus the alignment of the X-ray beam can move from being focused directly on the whole of the tumor, or other feature, to being off its target to a greater or lesser extent. The difference between on-target and slightly off-target need not be great. Even if the offset is very small, that difference can be critical to the success or failure of the treatment such as resection, or rendering the impinged tissue necrotic, or other treatment.
This situation is equally true for remote controlled and so called “surgeonless” operations that employ a solid scalpel rather than a radiation scalpel, such as a high energy X-ray beam. The scalpel is wielded by a remotely controlled machine that has been preprogrammed to follow a specific predetermined track or course, if the body being worked on moves during surgery, but the preprogrammed track has not been programmed to compensate for this movement, the scalpel will cut in the wrong place, at least part of the time. Also, when a remotely located surgeon is directly controlling the scalpel via remote-controlled means, and no preprogramming exists, real-time feedback of patient body motion is required to indicate to the remotely located surgeon, or to automated surgical equipment, that the patient or its organs have moved.
It is known in the surgical field that certain forms of surgery, particularly computer operated cranial image guided microneurosurgery, can be greatly assisted and improved by independently tracking the movements of a scalpel or probe while the functional ends of these instruments are out of line of sight of the surgeon. In this technique, these movements of the scalpel, or the like, are matched to the feature of the body that is being resected or rendered necrotic as it appears on a previously taken image of the portion of the intracranial tissue that is being resected or rendered necrotic (that is, the tumor). Thus, the probe or knife can be made to follow the contours of the diseased tissue as shown on a previously taken MRI, or the like, even where the surgeon cannot directly see the diseased tissue. Clearly it is very important that the patient's head be maintained absolutely still during the surgery, and this has been accomplished by severely clamping the head in suitable restraints prior to and during surgery. However, it is not always possible to maintain the cranium absolutely still during extended surgery.
It is also known (see U.S. Pat. No. 6,501,981 for example) to carry out treatments of internal features of a body while compensating for the inadvertent, or intentional, movement of the body during surgery. This reference discloses that this compensation is accomplished by periodically generating positional data about the internal target structure or feature that is being treated, continuously generating position data about the position of markers operatively associated with the body but positioned outside the body, and generating a correspondence between these sets of data.
As with most, if not all, medical instrumentalities, it is undesirable to employ an instrumentality with one patient that has been used by another patient. Further, it is important to use instrumentalities in connection with a patient that do not significantly adversely affect the treatment itself.